192 ACANTHINULA. 



Length 2, diam. 2 mm.; 4 whorls (France). 

 Length 2, diam. 2.3 mm.; 4 whorls (France). 

 Length 2, diam. 1.8 mm.; 4 whorls (Germany). 

 Length 1.75, diam. 2 mm. (France). 



Europe; Asia Minor and Transcaucasia; Algeria and Mo- 

 rocco. Pliocene, Montpellier; Pleistocene, England. 



Helix aculeata Muller, Vermium etc. Historia, ii, 1774, p. 

 81. — Kossmaessler, Iconogr., II, viii, p. 38, pi. 39, f. 536. — 

 Pfr., Monogr., i, p. 50. — Moquin-Tx\jstdon, Moll. France, ii, p. 

 189, pi. 15, f. 5-9.— Jeffreys, Brit. Conch., i, 1862, p. 176, 

 with var. albida. — "Westerlund, Nova Acta Soc. Sei. Upsal. 

 (3), viii, 1873, p. 58, with var. sublcevis. 



Acanthinula aculeata Kennard & "Woodward, Essex Nat- 

 uralist, x, 1897, p. 93 and table; Journ. of Conch., 1903, p. 

 354; Proc. Malac. Soc. London, viii, p. 91; Q. Journ. Geol. 

 Soc, vol. 75, 1919, p. 229 (Pleistocene and Holocene of Eng- 

 land).— Wenz, Fossilium Catal., Pt. 20, iii, p. 968 (Middle 

 Pliocene, Plaisancian: Montpellier). 



Helix spinulosa Lightfoot, Philos. Trans. Roy. Soc. Lon- 

 don, vol. 76, 1786, p. 166, pi. 2, f. 1-5.— Montagu, Test. Brit., 

 1803, p. 429, pi. 11, f. 10. 



Helix granatelli Bivona, Occhio, 1839, no. 9, f. 2 (teste 

 Pfeiffer; not seen by H. P.). 



Helix delectatilis Solander, according to Montagu, 1803, p. 

 430. 



Helix nucleata Turton, according to Montagu, 1. c. ; appar- 

 ently a typographical error for aculeata. 



A widely-spread and variable species. According to Muller, 

 who gave an excellent description, there should be 28 to 30 

 riblets on the last whorl. The specimen drawn in fig. 5 has 

 30. A German specimen, fig. 6, has 22. The filaments at the 

 shoulder are extremely variable in degree of development, 

 though rather constant, except as affected by wear, in single 

 colonies, in the material at hand. The thickness of the lip 

 also varies widely in different lots. I do not know that any 

 comparative study has been made of these variations, which 

 may be correlated with ecologic factors, or perhaps denote 

 minor races. 



Sicilian specimens seen, fig. 4, have very delicate riblets, 

 often largely deciduous, but when best preserved they bear 



